1. Technical Field
The present invention relates to a toner for development of an electrostatic image, a method for manufacturing the same, a developer for development of an electrostatic image, a toner cartridge, a process cartridge, and an image forming apparatus.
2. Related Art
Methods of visualizing image information via an electrostatic image, such as electrophotography, have been utilized in various fields at present. In electrophotography, an electrostatic image is formed on a photoreceptor by charging and exposure steps, and the electrostatic image is developed with a developer containing a toner for development of an electrostatic image (hereinafter referred to sometimes as simply “toner”) and visualized through transfer and fixation steps.
As the developer used herein, a 2-component developer consisting of a toner and a carrier and a 1-component developer using only a magnetic toner or a nonmagnetic toner are known. Usually, production of the toner uses a kneading pulverizing process that involves fusing and kneading a thermoplastic resin with a colorant, a charge control agent and a release agent such as wax, then cooling the mixture, finely dividing it and further classifying the divided particles.
If necessary, inorganic or organic fine particles are added sometimes to the surfaces of the toner particles in order to improve fluidity and cleanability. These methods can produce considerably superior toners.
From the viewpoint of low-temperature fixability, a toner by an emulsion polymerization aggregation process using a polyester resin having high sharp-melting properties has been proposed. This toner uses a crystalline polyester resin to achieve low-temperature fixability. However, colorant dispersibility therein is poor, and desired density is hardly achieved relative to the amount of the colorant added.